It may be hard to conceive of now, but there was once a lull in Mariah Carey’s superstar career. In 2001, her film “Glitter” was a commercial flop; the album that followed, 2002’s ...

After a long day of rehearsing for her upcoming world tour, Katy Perry decided to peruse a few books to help her unwind before bed. “I was listening to ‘Cosmos’ by Carl ...